Stability of Converter Control for Multiterminal HVDV Systems

The stability analysis of converter control, particularly for multiterminal HVDC systems, is complex and requires a systematic approach. This paper presents a new discrete converter model based on average system quantities and the development of the state space model of the AC/DC system. The linearized, discrete time, state space model of the overall system is derived utilizing the linearized component models and identifying the interconnections between them. Both frequency and time domain techniques are employed for stability investigations. The system model is demonstrated through the stability analysis of some sample systems and the results are validated using digital simulation.